Method of manufacturing electrostatic condensers



July 14', 1936.

w. B. WINES METHOD OF MANUFACTURING ELECTROSTATIC CONDENSER Filed Qct. 20, 1933 lNl/[WTO/P W. 5. WINES ATTORNEY Patented July 14,1936

PATENT OFFICE METHOD OF MANUFACTURING ELECTRO- STATIC CONDENSEBS William B. Wines, Elmhurst, 111., assignor to Western Electric Company, Incorporated New York, N. Y., a. corporation of New York Application October 2:0, 1933, Serial No. 694,505

14 Claims. (01.1175-41) This invention relates to a method of manufacturing electrostatic condensers, and is an improvement in the method of manufacturing condensers of the paper and foil rolled type disclosed in copendingapplication of R. E. Carlson, Serial No. 417,615, filed December 31, 1929, allowed August 21, 1933 and now Patent No. 1,948,331, February 20, 1934. e

In the above mentioned application a method of manufacturing condensers of the referred to type is disclosed which includes the step of applying a preliminary pressure to the rolled condensers prior to the baking or dehydrating and impregnating steps, thereafter dehydrating and impregnating the condensers, cooling the condensers to.

a predetermined temperature without substantial pressure, and then applying pressure until the 'condensers are completely cooled. This step of applying a preliminary pressure to the condensers prior to the dehyd ating and impregnating steps, coupled with the nal pressure, resulted in the capacity of the condensers being increased approximately 18% over prior. methods wherein no preliminary pressure was applied to the. con

densers.

The object of this invention is to increase the capacity for a given size. and weight of material of the above and similar types of condensers.

In accordance with one method of carrying out the present invention the steps of the method above described are substantially utilized but the method is modified by subjecting the condensers after the baking or dehydrating step and prior to being impregnated to a second pressure followed by a supplementary baking while the latter pressure is applied. Bypracticing the described method of the present invention there results a further appreciable increase in the capacity of the condensers over that'of the condensers manu=- factured in accordance with the method of the referred to application.

1 The invention will be more fully understood from the following description, taken in connection with the accompanying drawing, wherein Fig. 1 is a longitudinal vertical sectional view of a pressing apparatus used in practicing the method, and 7 Fig. 2 is an enlarged fragmentary plan view of the pressing apparatus shown in Fig. 1. A pressing apparatus used in practicing the method will be described first and more complete details of the method will follow.

The apparauts for preliminarily pressing the condensers as disclosed in the drawing comprises a compressor H! which is mounted on a suitable a frame IL the compressor consisting of a cylinder l2 closed at its ends by end plates I3 and M. A two-way piston l is'movably disposed in the cylinder l2 and is provided with a plunger rod 16 which extends through the end plate l3 and a packing gland which is carried thereby. A plunger head H is mounted on the outer end of the plunger rod it for a purpose hereinafter de-' scribed. Air lines or pipes l8 and I9 each have one of their ends disposed in communication with the cylinder l2 through the end plates l3 and Hi, respectively, while the other ends of the air lines or pipes l8 and i9 are connected to a valve 20 which may be termed as a four-way valve. An

' air supply line 21 is in communication with the valve 20 and is arranged to supply air under pressure to the cylinder. The valve is provided I with arcuate shaped passageways 22 and 23 which are arranged to connect the air lines it and it with the supply pipe M or to connect the air lines it and H) with an exhaust opening 24. A presand their spacing plates 33, and side members 3% for holding the condensers and plates against lateral displacement. I When producing the condensers 32 in accordance with this invention they are wound in the usual manner and placed by the operator within the rack 29, with their ends resting upon the bottom portion 3 l. The condensers are arranged in layers within the rack 29 and two nickel-silver plates 33 are disposed between each layer. The

rack 29 with the condensers and the separating plates 33 is then disposed upon the frame M with one end adjacent the abutting member 30 and" the other enddisposed so that the plunger head i! may enter an opening 35 within the rack. While in this position the valve 20 is actuated by a handle 36 which is moved from the dotted line position into the full line position shown in Fig. 1. This movement of the valve 30 will allow the air under pressure to pass from the supply pipe 2| through the arcuate shaped passageway 23, the air line l9, and into the cylinder it, thus forcing thepiston l5 toward the end plate l3 and forcing the plunger into the frame ll through the opening 35 and against the contents thereof.

. takes place.

While the valve 20 is in this position the air upon the opposite side of the piston l5 will be allowed to escape through the air line Hi, the passageway 22, and the exhaust opening 24. The condensers are subjected in this manner'to a pressure which is not sulficient to weaken the dielectric'strength or specifically to a, pressure of approximately 300 pounds resulting in a pressure of approximately 60 pounds per square inch on the sides of each unit or condenser. which has approximately 5 square inches of surface. It should be understood, however, that the amount of pressure may vary with the type of condenser employed, and also that a much higher pressure han that mentioned has been employed, for instance, a pressure of approximately eighty pounds per square inch on the sides of the condensers, with good results. In some types of condensers, such as, for instance, .the non-inductance type in which terminals are not inserted betweenv the paper and foil, considerably higher pressures may be used, since in such condensers there is no tendency for the terminals to disrupt the paper and foil at the high pressure.

' After the desired amount of pressure has been applied to the condensers 32, wedges such as those indicated at 31 are disposed between the end of the rack 29 and the condensers so as to retain the pressure. The plunger I1 is then removed from the rack 29 by moving the handle 36 into the'dotted line position and actuating the valve 20 so as to allow the piston l5 to return to its normal position. The rack 29 of condensers 32 is then removed from the frame I I and placed in a carrier which is transferred to a treating or impregnating tank (not shown), which consists of chambers internally heated by means of steam plates. The condensers are baked under atmospheric pressure for at least two hours at a temperature of 200 F. to 265 F., then under an absolute pressure of from 2 to 3 inches of mercury at approximately the same temperature for at least four hours, and thereafter under an absolute pressure of not more than /2 inch of mercury of the same temperature for at least one hour to thoroughly dehydrate them.

During the baking of the condensers 32 to dehydrate them the preliminary pressure may be entirely relieved or substantially so due to the shrinkage of the paper or otherdielectric ma terial used in the condensers. In order to take up this shrinkage the condensers are subjected to a second pressure immediately after the baking thereof before any appreciable The pressing apparatus l0 may be used to subject the condensers to the second pressure and in a manner similar to the operation thereof hereinbefore described in connection with the application of the preliminary pressure to the condensers. Therefore, immediately after the baking operation the rack 29 of condensers is transferredagain to the pressing apparatus I 9 and subjected to a second pressure, the wedges 31 being removed during the application of the pressure. Theamount of pressure applied to the condensers during the second pressing operation may be identical to that applied in the preliminary pressing operation, namely, approximately 60 pounds per square inch on the sides of each condenser, or it may be of a higher or lower order than the preliminary pressure. This second pressure may be app ied to the condensers without stressing the dielectric material any more than it was stressed during the preliminary pressure,

degree of cooling 7 which, as hereinbefore described, is not sufllcient to weaken the dielectric strength.

After the rack 29 of condensers 32 have been subjected to the desired amount of second pressure the wedges 31 are again disposed between 5 the end of the rack and the condensers so as to retain the pressure and the rack of condensers is again placed in the impregnating tank and subjected under a. vacuum to a supplementary baking thereof to bring them to the temperature to which they were subjected in the dehydrating operation previously described.

The impregnating tank is then filled with a compound while the vacuum is maintained and the condensers 32 are thus impregnated under an absolute pressure of notmore than inch mercury for at least two hours with the temperature remaining as stated above. The vacuum is then released from the condensers while remaining in the compound for approximately five minutes under atmospheric pressure and thereafter the compound is discharged from the tanks. After the condensers have drained slightly, they are removed to a hydraulic -press wherein they are subjected to pressure sufficient to take up the contraction of the condensers as they cool. In this press the condensers remain without substantial pressure until they cool to approximately 210 F. and thereafter a pressure of approximately 12 pounds per unit is applied, which results in a pressure of approximately 2 pounds per square inch on the sides of each unit, until they are cooled to 205 F., when the 12 pound pressure is raised to approximately 18 pounds and retained at this pressure until the temperature is reduced to 200 F. Again the pressure is increased to 30 pounds per unit and the condenser are allowed to cool under this pressure to 140 F., after which the rack 29 is removed and the condensers are separated. 40

The application of a preliminary pressure to the condensers, prior to, and while such pressure is applied during the baking or dehydrating step, the latter step followed by a second pressure and a supplemental baking thereof, and thereafter the treating or impregnating step of this method, while such second pressure is applied, coupled with the subsequent application of pressure, which is increased, during the cooling of the condensers, increases the capacity of the condensers an appreciable degree. The increase in the capacity of the condensers, by this method, not only makes it possible for condensers of a desired capacity to be manufactured smaller in size, so as to require less space during use, but reduces the cost of the condensers in view of the fact that less material is required in producing the condensers of the desired capacity. Furthermore with this method of manufacture, condensers may be increased in capacity without increasing the size thereof.

While the invention has been described with reference to a specific embodiment thereof, it is understood that various modifications may be made therein without departing from the spirit and scope of the present invention.

What is claimed is: t

1. A method of manufacturing condensers which comprises applying pressure to compress a condenser, heating the compressed condenser to expel moisture and gases, applying pressure to compress the condenser, heating the compressed condenser, impregnating the condenser, cooling the condenser to a predetermined temperature without substantial pressure, and then compressing an increasing vacuum to the compressed condenser while heating to expel moisture and gases,

again compressing the condenser, heating the condenser, impregnating the compressed condenser, cooling the condenser to a predetermined temperature without substantial compression, and then compressing. the condenser during the remainder of the cooling operation, the pressures of the preliminary and second compressions being higher than the final pressure.

3. A method of manufacturing condensers which comprises preliminarily compressing a condenser under a high pressure, heating the compressed condenser, compressing the condenser under a second high pressure, heating the condenser, impregnating the compressed condenser, cooling the condenser to a predetermined temperature, and then compressing the condenser under a relatively low pressure during the remainder of the cooling operation.

4. A method of manufacturing condensers which comprises preliminarily compressing 'a condenser, baking the compressed condenser, again compressing the condenser, baking the compressed condenser, impregnating the condenser at the residual pressure remaining from the second compression, cooling the condenscr,'.compressing the condenser during the cooling thereof, the preliminary and second pressures for compressing the condenser being higher than the final pressure.

'5. A method of manufacturing condensers which comprises preliminarily compressing a condenser under a pressure in the vicinity of sixty pounds per square inch, heating the compressed condenser to expel moisture and gases, again compressing the condenser, heating the condenser, impregnating the compressed condenser, cooling the condenser, and compressing the condenser under a relatively lower pressure during .the cooling operation.

6. A method 'of manufacturing condensers which comprises preliminarily compressing a condenser under a pressure in the vicinity of sixty pounds per square inch, heating the compressed condenser to expeTmoisture and gases, again compressing the condenser, heating the condenser, impregnating the compressed condenser, cooling the condenser, compressing the condenser under a pressure in the vicinity of two pounds per square inch during a portion of the cooling operation, and gradually increasing this pressure.

7. A method of manufacturing condensers which comprises preliminarily compressing a condenser, heating the compressed condenser to expel moisture and gases, again compressing the condenser, heating the condenser, impregnating the compressed condenser, and compressing the condenser under an increasing pressure during cooling, the pressures for the preliminary and second pressures being higher than the final pressure applied to the impregnated condenser.

8. A method of manufacturing condensers which comprises preliminarily compressing a condenser under a pressure of at least of the order of sixty pounds per square inch, baking the condenser while compressed, again compressing the 5 condenser under a pressure of at least of the order of sixty pounds per square inch, heating the con- 'denser, subsequently impregnating the compressed condenser, cooling the condenser, and compressing the condenser during the cooling thereof to compensate for shrinkage.

9. A method of manufacturing condensers which comprises preliminarily compressing a condenser, drying the compressed condenser, again compressing the condenser, heating the condenser, then impregnating the compressed condenser and compressing the condenser after impregnation.

10. A method of manufacturing condensers which comprises preliminarily compressing a condenser, drying the compressed condenser, again compressing the condenser, heating the condenser, subsequently impregnating the compressed condenser, cooling the condenser, and compressing the condenser during the cooling thereof to compensate for shrinkage.

11. A method of manufacturing condensers which comprises preliminarily compressing a condenser, baking the compressed condenser, again compressing the condenser, heating the condenser, impregnating the compressed condenser, cooling the condenser, and compressing the condenser during the cooling thereof, the pressures of the preliminary and second compressions being higher than the final pressure.

12. A method of manufacturing condensers which comprises preliminarily compressing a condenser under a pressure in the vicinity of eighty pounds per square inch, drying the compressed condenser, again compressing the condenser, drying the condenser, then impregnating the compressed condenser and compressing the condenser after impregnation.

13. A method of manufacturing condensers which comprises preliminarily compressing a condenser in the vicinity of eighty pounds per square inch, heating the compressed condenser to dehydrate the same, again compressing the condenser under a pressure in the vicinity of eighty pounds per square inch, reheating the compressed condenser, subsequently impregnating the compressed condenser, and compressing the condenser after impregnation.

14. A method of manufacturing condensers which comprises preliminarily compressing a condenser, heating the compressed condenser to dehydrate the same while compressed, again compressing the condenser,'reheating the condenser while compressed, impregnating the condenser while compressed at the residual pressure remainso ing from the second compression, cooling the con- I denser to a predetermined temperature without substantial pressure, and then compressing the condenser under an increase in pressure until the condenser is completely cooled. 5

WIILIAMB. WINES. 

